In recent years, flat display devices, such as liquid crystal display devices etc., have been widely used in various apparatuses, such as personal computers, mobile telephones, PDAs, game apparatuses, etc. There are also known display devices which detect information about a position on the display screen by using a touch panel (touch screen) provided on the flat display device. For example, Patent Document 1 describes a resistive touch panel.
Resistive touch panels include, for example, a pair of rectangular transparent substrates facing each other with there being a predetermined gap between the substrates. A frame region in which electrodes and interconnects are formed is formed on a peripheral portion of the pair of transparent substrates. A detection region for detecting a touch position is formed on the inner side of the frame region.
A transparent electrode made of indium tin oxide (ITO) etc. is formed on the inner surface of each transparent substrate in the entire detection region. Electrodes are formed in the frame region of one of the transparent substrates, extending along two opposite edges of that transparent substrate. Electrodes are formed in the frame region of the other transparent substrate, extending along two other opposite edges adjacent to the aforementioned two edges.
Terminals formed at one end of interconnects extended from the electrodes are all placed at a single portion in the frame region of the pair of transparent substrates. The region where the terminals are formed is referred to as a terminal region. A flexible printed circuit (FPC) is connected to the terminal region.
In this case, when the transparent electrodes of the pair of transparent substrate contact each other at a touch position, a voltage value sensed between the electrodes of one of the transparent substrates is detected through the transparent electrode of the other transparent substrate. Thus, the touch position is detected.
Incidentally, in the touch panel of Patent Document 1, in order to maintain electrical connection at a thermocompression bonding portion between the terminals and the FPC even in high temperature environments, a projection portion is formed on the transparent substrate, and the FPC is thermocompression bonded to the terminals in the terminal region which is formed in the projection portion.